A single touch line is not working anymore.

Matthias, it is my experience that if part of the digitizer does not work, the whole digitizer needs to be replaced. Of course, since you just worked on your phone, I would recommend that you double check your work first. IF you find that all connections are properly seated and all your cables are okay, it is time to replace the digitizer. I also would recommend to replace the front panel assembly, since it is a lot easier, quicker and less likely to fail. Here is the guide and the part is available right here, as well as many other places. Hope this helps, good luck.